I am looking at building a Brutus. Instead of direct firing my mash, I am thinking about recircing it through a coil in my HLT. Thinking this through in my head I am thinking I wont need a burner on my MT and that I can chill through the HLT.

Has this been done before? I am not finding anything in my searches. Do you have any build threads you can point me in the direction of?

There are a bunch of systems that use this. Kal's electric brewery is set up this way, although obviously that uses an electric heating element instead of gas. Although, he does use a separate chiller instead of reusing the HLT.

You will want something to recirculate or agitate the water in the HLT when you are recirculating your mash or you'll get some stratification in the HLT that will make it difficult to hit your target temps.

I think it's a pretty common configuration for HERMS. I don't currently have much in the way of pics, but that's pretty much how my system is set up. My HLT and MLT are both bottom drain to minimize deadspace, and the MLT is insulated with a couple layers of reflectix. The HEX coil is mounted in a lid. This way I can also use it as an IC, although I don't usualy chill that way. I fill the HLT with cold tap water and whirlpool through the HEX to knock off the first bit of heat. While that's going I fill the MLT with a couple bags of ice and a little water, and then move the HEX to the MLT to finish chilling.

This is basically what my system is. I have a HEX coil in the HLT and recirculate during the mash to maintain temps. No burner on the MLT. I heat strike water in the BK and transfer to MLT at the same time I heat the HLT to desired mash temp. Once my strike settles I recirculate through the HEX. I use my second pump to recirculate water from bottom to top in HLT to keep even temps. At mash out I just raise the temp in the HLT until the desired temp is reached in the MLT. At this point I move some lines so I can transfer wort from MLT to BK and water from the HLT to MLT for sparge. Water is all ready preheated in the HLT from the mash out to use for sparging. Once my desired volume is transferred from the HLT and start the boil I drain the HLT and fill with ice water. After boil I recirculate through HEX just like I do during the mash but into the BK. I can cool 6 gallons from boil to 50 degrees in 10 min. Wort never touches the inside of the HLT and the HEX is flushed after the cool with sanitizer an recirculated through all of the hoses. I would recommend drawing a picture of all your vessels with fittings and pumps and then write down a step by step description of your processes illustrating the configuration of your lines and this will help you design your system before you build. Do separate illustrations for each step so you do not miss anything. I found this very helpful being able to visualize each step. Once you have this you can break it down further into the smaller pieces that make up each line and connection. Search "MaxOut Brew Station" if you want to see details of my system as it sound similar to what you are thinking of.

This system seems cheaper (one less temp controller, one less burner, no need for plate chiller). No risk of scorching my mash. So why are there so many clones of Lonnies system?

What are the cons to this system compare to the Brutus 10?

Good questions and I agree. That’s why I went with HERMS.

I think most people do not use a controller on the BK burner. I use a BCS to control burners on the BK and HLT. In theory you could get away with one controlled burner on the HLT but for me would lengthen the brew day. I have temp probes in all three vessels and in the HEX out. I am able to maintain mash temps + or - 1 degree of error. I recirculate the entire mash time and can monitor the temp of the mash coming out of the HEX and in the MT. I find the gauges on the vessels to be inefficient during testing and would not have them at all in retrospect (although they look cool). I use 12" temp probes connected to BCS in all three vessels and a hand held to test for cold or hot spots.

I think the one drawback to a HEX for cooling is the availability/cost of ice. I have a large ice machine and played a role in my decision to go with the HEX for cooling or I would have gotten a plate chiller.

You could take a look at my build tread, linked in my sig. Basically a Brutus 10 HERMS setup. Ramping mash temp probably takes a little longer than on a direct fired MLT, but it hasn't been a problem for me. I've probably done about 20 batches on my brutus HERMS rig.

i do basically what you describe, except i don't mount the HEX coil in the HLT, i just use an immersion chiller (50' of 1/2"). it's a HEX coil when it's in the HLT but it's an immersion chiller in the BK at the end of the boil.

it seems to me that you don't have any way to keep the HLT cold when using it as a chiller unless you keep adding ice. as the wort heats the chill water during recirc you are simply heating the HLT. Max says 10 minutes to 50 degrees which is still pretty killer!

i was going to hard plumb my coil into my HLT but having it as an IC/HEX just seems to be easier. the only downside is having to physically move the coil from one container to the other... but i never have to worry about cleaning the inside of it which is a big plus.

This system seems cheaper (one less temp controller, one less burner, no need for plate chiller). No risk of scorching my mash. So why are there so many clones of Lonnies system?

What are the cons to this system compare to the Brutus 10?

I think the reason for the popularity of the brutus is the combination of it being a great system and the detailed plans being widely published. That doesn't make it the best sytem for everyone though.

IMO the main advantage it has over HERMS is the speed at which the temps can be raised for step mashes, mash-out, temp corrections, etc. Even though the original Brutus calls for two pumps, it can be built and operated with only one. A HERMS requires either a second pump or a stir mechanism to circulate the water in the HLT. Another advantage of the Brutus for the less DIY inclined is the availability of detailed plans and easy to follow instructions. And FWIW there's really no risk of a scorched mash with the Brutus unless the pump stops working and you fail to notice it for a while.

While the HEX in a HERMS can be used for chilling, it's not always the most effective or efficient method, which is why many HERMS owners use other methods to chill. My "cold" tap water is often in the 90's(F), so I'd need to recirculate ice water for chilling whether using a plate chiller, IC, CFC, or anything else, so using the HEX as a prechiller with water and then as a chiller with ice isn't much different than any other system for me. If I had cold tap water, I might not use the HEX to chill, or if I did it might be as an IC rather than running wort through it.

The reasons you mention along with my water situation are what pushed me towards a HERMS, and I don't regret it at all. Good luck with your build! Come back with any questions you have along the way, and be sure to post pics.